Three-dimensional structure formed with precision fold technology and method of forming same

ABSTRACT

A three-dimensional structure formed with precision fold technology includes a first sheet section having a first edge formed with a first joinder structure proximate the first edge, a second sheet section having a second edge formed with a second joinder structure proximate the second edge for interlocking engagement with said first joinder structure, and a plurality of folding structures formed in the sheet of material along a plurality of desired fold lines which divide the sheet of material into said first and second sheet sections, the folding structures being formed to produce sufficiently precise folding of the sheet of material along the fold lines to position the first and second edges together such that said first and second joinder structures interengage with one another and retain the sheet of material in a folded condition.

RELATED APPLICATIONS

This application is a Continuation-in-Part of U.S. patent application Ser. No. 11/357,934 filed Feb. 16, 2006 and entitled APPARATUS AND METHOD FOR JOINING THE EDGES OF FOLDED SHEET MATERIAL TO FORM THREE-DIMENSIONAL STRUCTURE, which is a Continuation-in-Part of U.S. patent application Ser. No. 10/795,077 filed Mar. 3, 2004 and entitled SHEET MATERIAL WITH BEND CONTROLLING DISPLACEMENTS AND METHOD FOR FORMING THE SAME and published as U.S. Patent Application Publication No. US 2004/0206152 A1, which is a Continuation-in-Part of U.S. patent application Ser. No. 10/672,766 filed Sep. 26, 2003 and entitled TECHNIQUES FOR DESIGNING AND MANUFACTURING PRECISION-FOLDED, HIGH STRENGTH, FATIGUE-RESISTANT STRUCTURES AND SHEET THEREFOR and published as U.S. Patent Application Publication No. US2004/0134250A1, which is a Continuation-in-Part of U.S. patent application Ser. No. 10/256,870 filed Sep. 26, 2002 and entitled METHOD FOR PRECISION BENDING OF SHEET MATERIALS, SLIT SHEET AND FABRICATION PROCESS and now U.S. Pat. No. 6,877,349, which is a Continuation-in-Part of U.S. patent application Ser. No. 09/640,267 filed Aug. 17, 2000 and entitled METHOD FOR PRECISION BENDING OF A SHEET OF MATERIAL AND SLIT SHEET THEREFOR and now U.S. Pat. No. 6,481,259, the entire contents of which applications and patent is incorporated herein by this reference.

This application claims priority to U.S. Provisional Patent Application No. 60/665,577 filed Mar. 25, 2005 and entitled THREE-DIMENSIONAL STRUCTURE FORMED WITH PRECISION FOLD TECHNOLOGY AND METHOD OF FORMING SAME, the entire contents of which is incorporated herein by this reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates, in general, to apparatus and methods for joining together the edges of sheet material which has been folded so as to form three-dimensional structures, and more particularly, relates to apparatus and methods for joining sheet material which has been folded using high-precision folding structures capable of accurately registering joinder structures for coupling together of sheet edges.

2. Description of Related Art

The Related Applications set forth above, and incorporated herein by reference, set forth in considerable detail apparatus and methods for bending or folding sheet material to form three-dimensional structures. Flat sheets are provided with a plurality of folding structures which will produce folding of the sheets along fold lines that can very precisely be controlled. The folding structures are typically slits, grooves or displacements that are positioned on alternating sides of a desired fold line so as to define spaced-apart bending or folding straps that precisely control folding of the sheet. Most preferably, the folding structures also produce edge-to-face engagement of the sheet material on opposite sides of the folding structures to further enhance folding precision and structural strength.

The folded sheets of the Related Applications often have been used to produce three-dimensional structures in which free or adjacent edges of the sheets are folded into abutting or overlapping relation and then are joined together to stabilize the resulting structure against unfolding. The previous techniques for securing the edges of the folded sheets together have varied considerably, depending upon the application, but in many instances the sheet edges have merely been joined together using standard fasteners such as screws, rivets, other mechanical fasteners, and/or welding, brazing or adhesives.

One of the very substantial advantages of the apparatus and method of the Related Applications is the ability to fold sheet material with both great precision and complexity using low folding forces. Precise and complex folding of sheet material allows techniques for joining the edges of the sheet material to be based upon precise registration of the edges at the end of the folding process so that joinder structures provided at, or proximate to the edges can be folded into registration with each other for the purpose of coupling the joinder structure together against separation of the edges.

The complexity with which sheets can be folded using the techniques set forth in the Related Applications allows a great reduction in the number of separate parts required to create a structure. Further reducing the number of parts by eliminating separate mechanical fasteners, therefore, is highly desirable, and elimination of separate welding, soldering and adhesive bonding steps also reduces the cost associated with the finished part.

Moreover, the precise sheet folding systems of the Related Applications can be applied to a wide range of sheet thicknesses. Thus, fastener-free sheet edge joining should also be capable of being used in applications requiring high strength joinder of the sheet edges.

What is needed is an apparatus and method to employ the ability to precisely fold sheet material in a manner which will allow fastener-free, high strength, low cost joinder of edges of the sheet material.

What is needed is an apparatus and method to provide an apparatus and method for forming enclosures or housings for various purposes, including the enclosure of electrical components, which apparatus and method lend themselves to efficient and low-cost manufacturing processes.

The apparatus and method of the present invention have other objects and features of advantage which will become apparent from, or are set forth in more detail in, the accompanying drawing and Detailed Description Of The Invention

BRIEF SUMMARY OF THE INVENTION

In summary, one aspect of the present invention is directed to a sheet of material formed for bending or folding into a three-dimensional structure. The sheet of material preferably includes a first sheet section having a first edge formed with a first joinder structure proximate the first edge, a second sheet section having a second edge formed with a second joinder structure proximate the second edge for interlocking engagement with said first joinder structure, and a plurality of folding structures formed in the sheet of material along a plurality of desired fold lines which divide the sheet of material into said first and second sheet sections, the folding structures being formed to produce sufficiently precise folding of the sheet of material along the fold lines to position the first and second edges together such that said first and second joinder structures interengage with one another and retain the sheet of material in a folded condition.

The first joinder structure may be a joinder tab extending out of the plane of the first sheet section forming a slot extending toward the first edge, and the second joinder structure may be a registration flange, a portion of which is dimensioned and configured to extend into the slot upon folding. The joinder tab may have a J-shaped cross-section. The joinder tab may be formed by stamping. The first sheet section may have an aperture formed by stamping the joinder tab out of the plane of the first sheet. The portion of the registration flange received in said slot may include a locking protrusion extending out-of-plane and dimensioned and configured to extend into the aperture to prevent disengagement of the first and second joinder structures. The locking protrusion may have a ramp-shaped profile to facilitate insertion of the portion of the registration flange into the slot. The folding structures may be provided by one of slits, grooves and displacements formed in the sheet of material to define a plurality of folding straps having center lines extending obliquely across the fold lines.

Another aspect of the present invention is directed to a sheet of material folded and secured to form a three-dimensional corner structure. The sheet of material preferably includes a first sheet portion folded along a first fold line to produce a first corner, the first sheet portion including an inwardly projecting coupling shoulder displaced out-of-plane forming a receiving slot, the coupling shoulder spaced from the first fold line, the first sheet further including an aperture formed by the out-of-plane displacement of the coupling shoulder, and a second sheet portion folded along a second fold line to produce a second corner member, the second sheet portion having a registration flange, a portion of which is received in the slot of the coupling shoulder, the registration flange portion having an outwardly projecting latch member spaced from the second fold line and extending into the aperture of the first sheet portion producing an interference fit between the coupling shoulder and the registration flange portion.

The first fold line and the second fold line may each be formed by a plurality of folding structures provided by one of slits, grooves and displacements defining a plurality of spaced apart folding straps having center lines extending obliquely across the fold lines to produce precise location of the coupling shoulder and latch member relative to the first fold line and precise location of the registration flange portion and the coupling shoulder slot.

The box formed utilizing precision fold technology of the present invention has other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated in and form a part of this specification, and the following Detailed Description of the Invention, which together serve to explain the principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a two-dimensional sheet material preformed with precision fold structures and fastening structures in accordance with the present invention.

FIG. 2 is a perspective view of the sheet material of FIG. 1, the sheet having undergone a first bending step.

FIG. 3 is a perspective view of the sheet material of FIG. 1, the sheet having undergone a subsequent bending step.

FIG. 4 is a perspective view of the sheet material of FIG. 1, the sheet having undergone another subsequent bending step.

FIG. 5 is a perspective view of the sheet material of FIG. 1, the sheet having undergone a further subsequent bending step.

FIG. 6 is an enlarged perspective view of the sheet material of FIG. 1, similar to FIG. 5, showing the internal engagement of the fastening structure.

FIG. 7 is a further enlarged perspective view of the sheet material of FIG. 1, similar to FIG. 6, showing the internal engagement of the fastening structure.

FIG. 8 is another enlarged perspective view of the sheet material of FIG. 1 showing the external engagement of the fastening structure.

FIG. 9 is a cross-sectional view of the fastening structure, taken substantially along line 9-9 of FIG. 7, before engagement.

FIG. 10 is a cross-sectional view of the fastening structure, taken substantially along line 10-10 of FIG. 7, before engagement.

FIG. 11 is a perspective view of a plurality of sheet material structures similar to that shown in FIG. 1 in a stacked configuration.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to those embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.

Turning now to the drawings, wherein like components are designated by like reference numerals throughout the various figures, attention is directed to FIG. 1, which shows a sheet material 30 having a generally cross-shaped configuration to form a box blank 31. In this embodiment, the sheet material has been dimensioned and configured to form an open box (see FIG. 5), however, one will appreciate that other three-dimensional can be formed in accordance with the present invention. For example, free standing corner structures can be formed, pyramid-shaped structure, and generally any three dimensional structure in which two planar, or substantially planar surfaces intersect one another.

The sheet material includes a first sheet section 32 having a first edge 33 formed with a first joinder structure 34 proximate the first edge. Preferably, the joinder structure is spaced a distance away from the adjacent fold line 35 thereby providing increased leverage to resist disengagement of the joinder structure as will become apparent below.

The sheet material includes a second sheet section 36 having a second edge 37 formed with a second joinder structure 38 proximate the second edge for interlocking engagement with said first joinder structure. The first and second joinder structures are dimensioned and configured to engage with one another upon folding the sheet material along the fold lines.

The sheet of material also includes a plurality of folding structures 39 formed in the sheet of material along a plurality of desired fold lines which divide the sheet of material into the first and second sheet sections. The folding structures are formed to produce sufficiently precise folding of the sheet of material along the fold lines to position the first and second edges together such that said first and second joinder structures interengage with one another and retain the sheet of material in a folded condition. Preferably, the folding structures are slits, grooves, displacements and or other suitable means formed in the sheet of material to define a plurality of folding straps 40 having center lines extending obliquely across the fold lines.

The particular configuration of the fold lines and folding straps are extensively discussed in U.S. patent application Ser. Nos. 10/795,077, 10/672,766, 10/256,870, and 09/640,267 (now U.S. Pat. No. 6,481,259), the entire contents of which applications and patent is incorporated herein by this reference.

As shown in FIG. 2, FIG. 3, FIG. 4 and FIG. 5, the two-dimensional sheet material is sequentially bent along respective fold lines to form an open box structure. First and second joinder structures are engaged as the sheet material is bent from the condition shown in FIG. 3 to the condition shown in FIG. 4. As can be seen in the figures, each corner of the box includes similar, cooperating joinder structures which are similarly engaged.

FIG. 7 and FIG. 8 are enlarged views of a corner of the box which clearly show the interengagement of the first and second joinder structures, the configuration of which are discussed in greater detail below.

Turning now to FIG. 9 and FIG. 10, first joinder structure is preferably a joinder tab 41 extending out of the plane of the first sheet section and forms a slot 42 extending toward the first edge. The second joinder structure is a registration flange, a portion 43 of which is dimensioned and configured to extend into the slot upon folding, as seen in FIG. 10.

In this embodiment, the joinder tab has a J-shaped cross-section 44, as can be seen in FIG. 9. One will appreciate that other cross-sectional shapes may be used including L-shapes, C-shapes and other suitable shapes. Preferably, the joinder tab is formed by stamping.

With continued reference to FIG. 9, the first sheet section has an aperture 45 formed as the joinder tab is stamped out-of-plane from the first sheet. The portion of the registration flange received in said slot includes a locking protrusion 46 extending out-of-plane and dimensioned and configured to extend into the aperture to prevent disengagement of the first and second joinder structures. Preferably, the locking protrusion has a ramp-shaped profile to facilitate insertion of the portion of the registration flange into the slot.

As shown in FIG. 11, the box blanks of the present invention may be shipped flat, thus allowing a plurality of box blanks to be stacked on top of one another. The configuration of the fold lines allows the box blanks to be folded from their two-dimensional state to their three-dimensional state on site. As is discussed in the above-mentioned Patent Applications, the precision fold lines allow the blanks to be folded, precisely, along predefined fold lines with minimal effort.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. 

1. A sheet of material formed for bending or folding into a three-dimensional structure, the sheet of material comprising: a first sheet section having a first edge formed with a first joinder structure proximate the first edge; a second sheet section having a second edge formed with a second joinder structure proximate the second edge for interlocking engagement with said first joinder structure; and a plurality of folding structures formed in the sheet of material along a plurality of desired fold lines which divide the sheet of material into said first and second sheet sections, the folding structures being formed to produce sufficiently precise folding of the sheet of material along the fold lines to position the first and second edges together such that said first and second joinder structures interengage with one another and retain the sheet of material in a folded condition.
 2. The sheet of material as defined in claim 1 wherein, the first joinder structure is a joinder tab extending out of the plane of the first sheet section forming a slot extending toward the first edge, and the second joinder structure is a registration flange, a portion of which is dimensioned and configured to extend into the slot upon folding.
 3. The sheet of material as defined in claim 2, wherein the joinder tab has a J-shaped cross-section.
 4. The sheet of material as defined in claim 2, wherein the joinder tab is formed by stamping.
 5. The sheet of material as defined in claim 4, wherein the first sheet section has an aperture formed by stamping the joinder tab out of the plane of the first sheet.
 6. The sheet of material as defined in claim 5, wherein the portion of the registration flange received in said slot includes a locking protrusion extending out-of-plane and dimensioned and configured to extend into the aperture to prevent disengagement of the first and second joinder structures.
 7. The sheet of material as defined in claim 6 wherein, the locking protrusion has a ramp-shaped profile to facilitate insertion of the portion of the registration flange into the slot.
 8. The sheet of material as defined in claim 1 wherein, the folding structures are provided by one of slits, grooves and displacements formed in the sheet of material to define a plurality of folding straps having center lines extending obliquely across the fold lines.
 9. A sheet of material folded and secured to form a three-dimensional corner structure, the sheet of material comprising: a first sheet portion folded along a first fold line to produce a first corner, the first sheet portion including an inwardly projecting coupling shoulder displaced out-of-plane forming a receiving slot, the coupling shoulder spaced from the first fold line, the first sheet further including an aperture formed by the out-of-plane displacement of the coupling shoulder; and a second sheet portion folded along a second fold line to produce a second corner member, the second sheet portion having a registration flange, a portion of which is received in the slot of the coupling shoulder, the registration flange portion having an outwardly projecting latch member spaced from the second fold line and extending into the aperture of the first sheet portion producing an interference fit between the coupling shoulder and the registration flange portion.
 10. The assembly as defined in claim 9 wherein, the first fold line and the second fold line are each formed by a plurality of folding structures provided by one of slits, grooves and displacements defining a plurality of spaced apart folding straps having center lines extending obliquely across the fold lines to produce precise location of the coupling shoulder and latch member relative to the first fold line and precise location of the registration flange portion and the coupling shoulder slot. 